In the past, the isolation of vibrations established by an energized electric motor from a supporting structure therefor has been accomplished in various different manners, see for instance U.S. Pat. Nos. 2,840,329 (Wightman), 2,904,289 (Refice), 3,235,207 (Church) and 3,750,267 (Otto), all of which are assigned to the assignee of the present application.
At least some of the prior art motors had hubs integrally formed and axially extending from opposite end frames of such a motor with fixed type bearings, such as a sleeve bearing or the like for instance, disposed within such hubs, and resilient motor mounts were secured by suitable means about such hubs and received in a cradle or the like for supporting the motor thereby to resiliently isolate the cradle from vibrations of the motor upon energization thereof. Although these past resilient motor mounts undoubtedly exhibited many salient features, it is believed that at least one disadvantageous or undesirable feature of such resilient motor mounts when secured by bonding or the like directly onto the end frame hub was that an additional retaining ring or the like was necessarily secured to such hub to prevent the displacement of such resilient motor mounts therefrom.
In others of the prior art motors, sleeve members (in the form of the above discussed hub) were secured to the opposite end frames so as to extend generally axially therefrom, and such sleeve members were splined for anti-rotational engagement with complementary splines provided in the resilient motor mounts which were received in a cradle supporting the motor in the manner discussed above. While this type of construction undoubtedly provided many salient features, at least one of the disadvantageous or undesirable features thereof is believed to be the added cost involved with respect to the provisions of such splined sleeve and the complexity of assembling it with the motor. In this vein, the aforementioned Otto patent utilized an annulus press fitted into the desired position thereof about a sleeve member connected to a motor end frame so as to extend axially therefrom, and flanges on the annulus were deformed into gripping or anti-rotational engagement with an associated resilient motor mount in response to the press-fitting of the annulus about the sleeve member. Undoubtedly, this type of past construction also exhibited many salient features, but one of the disadvantageous or undesirable features thereof is also believed to involve the added cost with respect to the provision of such annulus and the complexity of assembling it with the motor.
While the above discussed prior art constructions undoubtedly exhibited many salient features, as previously mentioned it is believed that such prior art constructions failed to address a disadvantageous or undesirable feature involving swivel torque of resilient motor mounts or cushioning devices when they are secured about integral hub portion of opposite end frames on a motor and also received in the cradle for supporting the motor.